Drying apparatus.



F. W. BARTLETT.

DRYING APPARATUS.

APPLIoATIoN FILED SEPT. 27, 191s.

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nanna-aren wnanTLnr'r, lor CALDWELL, NEW JERSEY.

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@pacification of Letters Patent.

Patented Jan. 5, 1915..

Application led September 27, 1913. Serial No. 792,206.

To all 'whom it may concern l Be i known that ll, FREDERICK W. Barr- Lnr'r, a citizen of the United States, res1d1ng at borough of Caldwell, in the county of Essex and State of .New Jersey, have invented certain new and useful Improvements in Drying Apparatus, of which the following is a specification.

This invention relates to apparatus used in the manufacture of vacuum bottles, that is to say, bottles or receptacles having a double wall with an evacuated space between the inner and outer walls. Such receptacles are made by inserting a smaller receptacle within a larger one and then sealing together their upper edges. The inner surface ofthe outer vessel and the outer surface of the inner one are then coated with a reecting material such as a deposit of silver, and the space intervening between said vessels or receptacles is then exhausted of air. The ordinary method of doing this is to subject the bottles to heat while pumping out the air. This merely makes them hot without drivinglout, to any great extent, the moisture and the gases. The result is to prolong the pumping operation at considerable expensev of time and power, without giving uniform and satisfactory results. l have found that a large part of the time consumed in pumping out the air is owing to the fact that the receptacles have not been yproperly dried before the pumping opera- Y tion is effected, and the object of the pres;

ent invention is to shorten'this step in the manufacture of such articles.

The' invention consists in a method of procedure and an apparatus for carrying out such method. Briefly stated, I drive o' the moisture by subjecting the receptacles to a vacuum and to hot dried air alternately, these operations being repeated at regular intervals. I nd in actual practice that T can cut down the time from sixty orseventy minutes to about thirty minutes, thus doubling the production in a given period.

The apparatus which T have invented .to carry outthis method comprises an oven containing suitable racks to hold the bottles or other receptacles, with means for heating said oven quickly to a temperature of about six hundred degrees Fahrenheit. This is a greater temperature than that to which they are subjected in the iinal pumping operation.

In other words, I subject the bottles to a greater heat while they are being dried, and drive 0H the gases at such 4gases will not be given oft' later in the iinal^pump1ng oven where the temperature 1s lower. In this way, ll do work outside of the inal pumplng oven which does not properly belong to 1t, and thereby increase the output of the apparatus.

In the accompanying drawing, Figure 1 1s a longitudlnal section of my pre-pumping oven, Fig. 2 is a cross section of the same, Fig. 3 A1s adiagram of the piping and the controlling valve, and Fig. 4c is a cross section of a pipe.

The oven consists of a, suitable box 1 mounted on a framework 2 and capable of be1ng opened for the purpose of inserting and removlng the bottles. The box is preferably made of sheet metal with a lining 3 of refractory material, such as asbestos.

lI prefer to divide the box on a diagonal plane, so that the front 4 and top 5 are secured to trlangular end portions 6. This part of the box is hinged at 7 at the lower edge of the front, and can be opened outwardly, resting when open upon brackets 8 forming part of the framework.

Along the middle of the bottom of the box extends a gas burner consisting preferably of two pipes v9 terminating near the center of the box and each provided on its upper side with a row of small orifices, whichmay be provided with tips 10. A gas pipe l' is connected with the outer end of each pipe, the supply of gas being regulated by a cock 12, while the air is controlled by a rotary inlet valve 13.

One ormore racks run lengthwise of the box, preferably one on either side of the gas burners, each rack consisting of longitudinal side bars 14 mounted on uprights 15 and connected at intervals by cross bars 16. The spaces between the side bars in each rack are the same as between the cross bars, so that a plurality of square openings are formed, each opening being of a size to receive easily a bottle 17. In the vertical central axis of each space a hole 18 is formed in the bottom of the oven to receive the tubulature 19 which projects from the lower end ,of the outer vessel. Under each row of holes is a tube 20 having a series of nipples 21 which receive the projecting ends of said tubulatures and make a gas-tight joint therewith. The tubes 20 are preferably i11- this high heat, so that clined so that the moisture extracted from the bottles can be drained off through drip cocks 22 at their lower ends. A cross pipe 23 connects the tubes 20 and both tubes are connected by a pipe 24 with a three-way l'erably jacketed with 4an insulating cover- 'ing 29 as shown in Fig. l, to prevent radiation.

AA vacuum pump, conventionally represented at in Fig. 3, is connected by a pipe 31 with the three-way cock 32. A suitable casing 33 incloses said cock and also a timing device for automatically operating the same at predetermined intervals. This device is preferably a cam 34 rotated by a pulley 35 and belt 36 from some suitable motor (not shown). The cam actuates a lever 37 whose free end is connected by a rod 38 with the arm 39 on .the spindle of the cock. The barrel of the cock contains a port 40 which inone position connects the pipe 24 with the vacuum pipe 31 and in its other position with the hot dry air pipe 28; the pipe not so connected being shut off.

The operation is as follows z--The bottles are placed in the racks with their tubulatures projecting down through the holes 18 and 'making a tight joint with. the nipples 21. The gas burners are lighted and the oven closed. The air inside quickly heats up to several hundred degrees Fahrenheit. The three-way cock is turned to therA position shown in Fig. 3, connecting the bottles with the vacuum pump, which extracts a portion of the moisture and gases from the spaces between the inner and outer receptacles. At'the end of a predetermined time 'the timing mechanism` shifts the cock so that'the vacuum is shut ofi' and the pipe 28 connected to the bottles. A current of dry air is drawn, by the vacuum remaining in the bot-v tles, through the hot heating pipes, filling the spaces between the receptacles with the hot dry air, which rapidly absorbs a portion of the moist gases left in such spaces. The ytiming ymechanism presently shuts off the hot air and opens the spaces to the vacuum pump again, whereby the moisture laden vhot air is sucked out. These alternate heatings and evacuatings are repeated for :say half an hour at intervals of a few minutes, resulting in a thorough drying out of the bottles and preparing them for the nal pumping and sealing ofi', which will occupy unich less time than by the old method.

In accordance with the provisions of the patent statutes, I have described the prinn cipl'e of operation of my invention, together ff with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. Apparatus for preparing double walled vessels for final evacuation, comprising a support for said vessels, a tubeliaving nipples adapted to make connection with said vessels, means for creating a vacuum in said tube, and means for heating air and admitting it to said tube.

2. Apparatus for preparing double walled vessels for final evacuation, comprising an oven having holes in its bottom, a tube having nipples in line with said holes, means for creating a vacuum in said tube, and means for heating air and admitting it to said tube.

3. Apparatus for preparing double walled Vessels for nal evacuation, which comprisesl having nipples in line with said holes,

means for connecting said tube with a source of vacuum, air heating pipes in said oven, means for connecting said heating pipes with said tube, and means for effecting said connections alternately.

5. Apparatus for preparing double walled vessels for final evacuation, which comprises an oven having holes in its bottom, a tube having nipples in line with said holes, means for connecting said tube with a source of vacuum, air heating pipes in said oven, means for connecting said heating pipes with said tubes, and means for automatically effecting said connections alternately.

6. Apparatus `for preparing double walled vessels for final evacuation, which comprises an oven having holes in its bottom, a tube having nipples inline with said holes, a pipe leading from a source of vacuum, a pipe leading from a source of hot dry air, and a three-way cock for connecting said pipes alternately with said tube.

7. Apparatus for preparing double walled vessels for final evacuation', which comprises an oven having holes in its bottom, a tube having nipples in line with said holes, a.

pipe leading from a source of vacuum, a pipe leading from a source of hot dry air, a three-Way cock for connecting said pipes alternately with said tube, and an automatic timing device for actuating said cock.

8. Apparatus for preparing double walled vessels for final evacuation, comprising a box having holes in its bottom, a rack extending lengthwise of said box in line with said holes, a gas burner along the bottom of said box, heating pipes at one side of said box, a tube underneath said box having nipples in line with said holes, a pipe leading from a source of vacuum, and a threeway cock for connecting said pipe and said heating pipes alternately with said tube.

9. Apparatus for preparing double walled vessels for final evacuation, comprising a box having holes in its bottom', a rack ex tending lengthwise of said box in line with said holes, a gas burner along the bottom of said box, heating pipes at one side of said box, a tube underneath said box having nipples-in line with said holes, a pipe lead ing from a source of vacuum, a three-way cock for connecting said pipe and said heating pipes alternately with said tubes, and a power-driven cam for actuating said cock at predetermined intervals. A

ln testimony whereof I aiix my signature in presence of two witnesses.

FREDERICK W. BARTLETT. 

